We have a new publication, Quantitative Analyses of Retinal Vascular Area and Density after Different Methods to Reduce VEGF in a Rat Model of Retinopathy of Prematurity in IOVS. Authors are: Haibo Wang, Zhihong Yang, Yanchao Jiang, John G. Flannery, Scott Hammond, Tal Kafri, Sai Karthik Vemuri, myself and M. Elizabeth Hartnett.
The images in the manuscript and above came out of some work that I posted an image for a while ago looking at ways to quantify the vascular arcades of the retina through image processing.
Abstract: Purpose: Targeted inhibition of Müller cell (MC)-produced VEGF or broad inhibition of VEGF with an intravitreal anti-VEGF antibody reduces intravitreal neovascularization in a rat model of ROP. In this study, we compared the effects of these two approaches on retinal vascular development and capillary density in the inner and deep plexi in the rat ROP model. Methods: In the rat model of ROP, pups received one-microliter of 1) subretinal lentivector-driven shRNA to knockdown MC-VEGFA (VEGFA.shRNA) or control luciferase shRNA, or 2) intravitreal anti-VEGF antibody (anti-VEGF) or control IgG. Analyses of lectin-stained flat mounts at p18 included: vascular/total retinal areas (retinal vascular coverage) and pixels of fluorescence/total retinal area (capillary density) of the inner and deep plexi determined with the Syncroscan microscope, and angles between cleavage planes of mitotic vascular figures labeled with anti-phosphohistone H3 and vessel length. Results: Retinal vascular coverage and density increased in both plexi between p8 and p18 in room air (RA) pups. Compared to RA, p18 ROP pups had reduced vascular coverage and density of both plexi. Compared to respective controls, VEGFA.shRNA treatment significantly increased vascular density in the deep plexus, whereas anti-VEGF reduced vascular density in the inner and deep plexi. VEGFA.shRNA caused more cleavage angles predicting vessel elongation and fewer mitotic figures, whereas anti-VEGF treatment led to patterns of pathologic angiogenesis. Conclusions: Targeted treatment with lentivector-driven VEGFA.shRNA permitted physiologic vascularization of the vascular plexi and restored normal orientation of dividing vascular cells, suggesting that regulation of VEGF signaling by targeted treatment may be beneficial.